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🔗 Aviation 🔗 Aviation/Aviation accident 🔗 Africa/Angola 🔗 Africa

On 25 May 2003, a Boeing 727, registered N844AA, was stolen at Quatro de Fevereiro Airport, Luanda, Angola. Its disappearance prompted a worldwide search by the United States' Federal Bureau of Investigation (FBI) and Central Intelligence Agency (CIA). No trace of the aircraft has since been found.

🔗 Books 🔗 Women's History

Around the World in Seventy-Two Days is an 1890 book by journalist Elizabeth Jane Cochrane, writing under her pseudonym, Nellie Bly. The chronicle details her 72-day trip around the world, which was inspired by the book, Around the World in Eighty Days by Jules Verne. She carried out the journey for Joseph Pulitzer's tabloid newspaper, the New York World.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Engineering 🔗 Photography 🔗 Photography/History of photography

The rapatronic camera (a portmanteau of rapid action electronic) is a high-speed camera capable of recording a still image with an exposure time as brief as 10 nanoseconds.

The camera was developed by Harold Edgerton in the 1940s and was first used to photograph the rapidly changing matter in nuclear explosions within milliseconds of detonation, using exposures of several microseconds. To overcome the speed limitation of a conventional camera's mechanical shutter, the rapatronic camera uses two polarizing filters and a Faraday cell (or in some variants a Kerr cell). The two filters are mounted with their polarization angles at 90° to each other, to block all incoming light. The Faraday cell sits between the filters and changes the polarization plane of light passing through it depending on the level of magnetic field applied, acting as a shutter when it is energized at the right time for a very short amount of time, allowing the film to be properly exposed.

In magneto-optical shutters, the active material of the Faraday cell (e.g. dense flint glass, which reacts well to a strong magnetic field) is located inside an electromagnet coil, formed by a few loops of thick wire. The coil is powered from a pulse forming network by discharging a high-voltage capacitor (e.g. 2 microfarads at 1000 volts), into the coil via a trigatron or a thyratron switch. In electro-optical shutters, the active material is a liquid, typically nitrobenzene, located in a cell between two electrodes. A brief impulse of high voltage is applied to rotate the polarization of the passing light.

For a film-like sequence of high-speed photographs, as used in the photography of nuclear and thermonuclear tests, arrays of up to 12 cameras were deployed, with each camera carefully timed to record sequentially. Each camera was capable of recording only one exposure on a single sheet of film. Therefore, in order to create time-lapse sequences, banks of four to ten cameras were set up to take photos in rapid succession. The average exposure time used was three microseconds.

🔗 Novels 🔗 Children's literature 🔗 Novels/Short story

Winnie-the-Pooh (1926) is the first volume of stories about Winnie-the-Pooh, written by A. A. Milne and illustrated by E. H. Shepard. The book focuses on the adventures of a teddy bear called Winnie-the-Pooh and his friends Piglet, a small toy pig; Eeyore, a toy donkey; Owl, a live owl; and Rabbit, a live rabbit. The characters of Kanga, a toy kangaroo, and her son Roo are introduced later in the book, in the chapter entitled "In Which Kanga and Baby Roo Come to the Forest and Piglet has a Bath". The bouncy toy-tiger character of Tigger is not introduced until the sequel, The House at Pooh Corner.

In 2003, Winnie the Pooh was listed at number 7 on the BBC's survey The Big Read.

🔗 Physics 🔗 Physics/relativity 🔗 Chemistry

Relativistic quantum chemistry combines relativistic mechanics with quantum chemistry to explain elemental properties and structure, especially for the heavier elements of the periodic table. A prominent example of such an explanation is the color of gold: due to relativistic effects, it is not silvery like most other metals.

The term relativistic effects was developed in light of the history of quantum mechanics. Initially quantum mechanics was developed without considering the theory of relativity. Relativistic effects are those discrepancies between values calculated by models that consider and that do not consider relativity. Relativistic effects are important for the heavier elements with high atomic numbers. In the most common layout of the periodic table, these elements are shown in the lower area. Examples are the lanthanides and actinides.

Relativistic effects in chemistry can be considered to be perturbations, or small corrections, to the non-relativistic theory of chemistry, which is developed from the solutions of the Schrödinger equation. These corrections affect the electrons differently depending on the electron speed relative to the speed of light. Relativistic effects are more prominent in heavy elements because only in these elements do electrons attain sufficient speeds for the elements to have properties that differ from what non-relativistic chemistry predicts.

🔗 Internet culture 🔗 Skepticism

Time Cube was a personal web page, founded in 1997 by the self-proclaimed "wisest man on earth," Otis Eugene "Gene" Ray. It was a self-published outlet for Ray's theory of everything, called "Time Cube," which polemically claims that all modern sciences are participating in a worldwide conspiracy to teach lies, by omitting his theory's alleged truth that each day actually consists of four days occurring simultaneously. Alongside these statements, Ray described himself as a "godlike being with superior intelligence who has absolute evidence and proof" for his views. Ray asserted repeatedly and variously that "academia" had not taken Time Cube seriously.

Otis Eugene Ray died on March 18, 2015 at age 87. Ray's website domain names expired in August 2015, and Time Cube was last archived by the Wayback Machine on January 12, 2016. (January 10–14)

🔗 Aviation 🔗 New Zealand

On 22 December 1978, a small Cessna 188 aircraft, piloted by Jay Prochnow, became lost over the Pacific Ocean. The only other aircraft in the area that was able to assist was a commercial Air New Zealand flight. After several hours of searching, the crew of the Air New Zealand flight located the lost Cessna and led it to Norfolk Island, where the plane landed safely.

🔗 United States/U.S. Government 🔗 United States 🔗 Law 🔗 Lists

A national emergency is a situation in which a government is empowered to perform actions not normally permitted. The 1976 National Emergencies Act implemented various legal requirements regarding emergencies declared by the President of the United States.

Between the enactment of the National Emergencies Act in 1976 through March 13, 2020, 61 emergencies have been declared; 27 have expired while 34 are currently in effect, each having been renewed annually by the president.

🔗 Mathematics

Sexy primes are prime numbers that differ from each other by 6. For example, the numbers 5 and 11 are both sexy primes, because 11 - 5 = 6.

The term "sexy prime" is a pun stemming from the Latin word for six: sex.

If p + 2 or p + 4 (where p is the lower prime) is also prime, then the sexy prime is part of a prime triplet.

🔗 Germany 🔗 Archaeology 🔗 Visual arts

The Löwenmensch figurine or Lion-man of the Hohlenstein-Stadel is a prehistoric ivory sculpture discovered in the Hohlenstein-Stadel, a German cave in 1939. The German name, Löwenmensch, meaning "lion-human", is used most frequently because it was discovered and is exhibited in Germany.

The lion-headed figurine is the oldest-known zoomorphic (animal-shaped) sculpture in the world, and the oldest-known uncontested example of figurative art. It has been determined by carbon dating of the layer in which it was found to be between 35,000 and 40,000 years old, and therefore is associated with the archaeological Aurignacian culture of the Upper Paleolithic. It was carved out of mammoth ivory using a flint stone knife. Seven parallel, transverse, carved gouges are on the left arm.

After several reconstructions that have incorporated newly found fragments, the figurine stands 31.1 cm (12.2 in) tall, 5.6 cm (2.2 in) wide, and 5.9 cm (2.3 in) thick. It currently is displayed in the Museum Ulm, Germany.